Silence of the wasps: How DNA could be key to stopping this NZ scourge

The European paper wasp (pictured) is mainly found around the Nelson region and is thought to have been in the country for a decade at least. Photo / Alvesgaspar/ CC BY-SA 3.0

It's one of our most notorious recent arrivals – but the European paper wasp could soon meet one of the most sophisticated pesticides ever designed.

The yellow and black menace is about to become the target of next generation of pesticides that aim to kill the wasp at its molecular roots, using the latest "gene-silencing" science.

The wasp is mainly found around the Nelson region and is thought to have been in the country for a decade at least.

It's seen as a serious scourge not just as an invasive species, but one that causes a particular headache for anyone whose home it moves into.

"While we already have the Asian and Australian paper wasps here, it's how they mass their populations that sets them apart," Victoria University insect ecologist Professor Phil Lester said.

"A house might have 20 nests around its eaves – that's a lot of wasps. They also tend have much larger nests, because they start earlier in summer."

The wasp also posed a major risk to our environment, given they likely fed on native insects and competed with our own species.

"If they spread throughout New Zealand, they're going to be a major problem for us."

But Lester and fellow scientists aim to stop the wasp in its tracks, with a cutting-edge agent drawing on gene silencing, or RNAi - a highly targeted and environmentally safe way to wipe out pest insects.

Lester's team plan to create short, synthetic segments of ribonucleic acid, or RNA – a molecule essential in coding and regulating the expression of genes.

Fed to the wasps through an attractive bait, their double-stranded RNA would mimic that found in the wasps themselves – but instead of doing jobs like creating proteins, they'd do the opposite.

"It's merely stopping cellular processes from working. It might mean stopping messages reaching their cells so they can make essential proteins, carbohydrates or chemicals that it needs to survive.

"It might mean they're not able to make an exoskeleton. Or it might stop them from being able to convert to sugar into energy."

Lester pointed out that, as the genomic information of the wasp wasn't being changed, the approach couldn't be considered genetic modification.

Moreover, the technology has the promise of being able to kill one species without the risk of harming others.

Richard Toft, the insect ecologist behind the revolutionary wasp bait Vespex, would help design an attractant, while respected Otago University geneticist Professor Peter Dearden would collaborate on the gene silencing solution.

"If we can develop a new bait alone, it could be mixed with a normal pesticide to kill wasps – but we are really aiming to go much further than that," Lester said.

"We are talking about the next generation of pesticides here."

The study is one of two new projects which have received million-dollar grants through the Government's Endeavour Fund.

The other, led by Plant and Food Research, aims to reveal the sex pheromones of New Zealand's two main vespula wasp species, so they can be exploited through a new biocontrol agent.